Grandstream HT813 FXO ATA – Hybrid Analog Telephone Adapter with VoIP and PSTN Support

The Grandstream HT813 is a high-quality hybrid Analog Telephone Adapter (ATA) designed for residential and small office environments, combining 1 RJ11 FXS port for analog telephone connection and 1 RJ11 FXO PSTN line port to provide vital backup lifeline support. This innovative device enables seamless continuity of telephone service during power outages by hard-relaying the FXS port to the FXO PSTN line, ensuring uninterrupted communication.

Featuring dual 10/100Mbps LAN and WAN Ethernet ports with an integrated NAT router, the HT813 offers reliable network integration and strong security with AES encryption and a unique security certificate for each unit. The adapter supports two SIP profiles simultaneously across the FXS and FXO ports, facilitating flexible and efficient VoIP deployments.

Key advanced features include 3-way voice conferencing per port, T.38 Group 3 fax relay (up to 14.4kbps) with fallback to G.711 for fax pass-through, automated and secure provisioning such as TR-069, and failover SIP server support to maintain continuous SIP service. The small form factor and versatile provisioning options make this device an excellent choice for upgrading traditional analog telephony to modern VoIP technology without sacrificing reliability or security.

Ideal for:

• Small businesses and residential users upgrading to VoIP


• Environments requiring backup PSTN line lifeline support


• Secure and flexible VoIP phone system integrations

Key Features:

• 1x RJ11 FXS port and 1x RJ11 FXO PSTN line port with lifeline support


• Support for 2 SIP profiles (FXS and FXO)


• Dual 10/100Mbps LAN and WAN ports with integrated NAT router


• Lifeline hard-relay functionality ensuring service during power outages


• 3-way voice conferencing per port


• T.38 Group 3 Fax Relay with automatic G.711 fallback


• Automated secure provisioning (e.g., TR-069)


• Failover SIP server for service reliability


• AES encryption with individual security certificates